控制色散的波导结构分析

色散控制在光纤通信中越来越重要,从低速率到高速率,从单波长SDH到多波长DWDM,色散控制要求越来越严.通过对不同应用的光纤波导结构的制造、性能测试和分析,指出了波导结构设计与光纤衰减、模场直径、弯曲损耗和波导色散等的关系.这些实践经验可以指导光纤的设计与制造.     

Optical Measurement Techniques for Optical Fiber and Waveguide Devices

We describe three major optical characterization methods for fiber and fiber devices. A simple servo controlled scanning fiber-optic confocal microscope is proposed for determining the refractive index profile of an optical fiber. To measure the chromatic dispersion of a short length fiber a Mach-Zehnder fiber interferometer with a novel interferometric distance meter is introduced. At the end, a tomographic method is demonstrated for determining the 2-D stress profile of a fiber.     

环形光纤激光器中的半导体光波导调制器

对环形光纤激光器中的半导体光波导调制器进行了理论研究，结果表明，光纤环中的偏振控制器对光的偏振态的控制以及半导体光皮导对光的偏振态的调节构成了激光器的主要调制机理，为环形光纤激光器的自调Ｑ及锁模的新机制提供了理论依据。     

Waveform Distortions in Femtosecond Laser Pulses Transmitting through Coated Optical Fiber Probes

We calculate the light field in metal-coated optical fiber probes under illumination of femtosecond laser pulses with the three-dimensional finite-difference time-domain method. By choosing the maximum of the calculated light field data in the time period of one light wave cycle at each spatial point, we obtain the amplitude distributions instead of the conventional light field distribution of a time instant. It is found that with an incident plane wave pulse of y-polarization, the output amplitude distributions of y-polarization have roughly a circled-cross-like pattern with two arc-like zero-amplitude zones. By analyzing the y-polarized waveforms versus time at the points near the arc-like zero-amplitude zones, we find that waveform distortions appear at points in the neighborhood of the zero amplitude lines and in the time intervals when two wave-packets overlap.     

传像光纤束单丝芯径大小对光纤像面全息图的影响

光纤像面全息可以获得较高衍射效率的全息图和再现较大的物像。文中分析了相干光激励下传像光纤束单丝芯径的大小对其输出光场的影响，以及输出光场中低阶模与高阶模对全息照相的不同作用，在此基础上，提出缩小传像束单丝芯径，增多单丝根数，可以提高光纤像面全息图衍射效率和分辨率的观点，并通过实验进行了验证。     

EDFA Gain-Flattening Using Side-Polished Fiber Half-Coupler With an Overlay Waveguide

We report fabrication and modeling of a fiber half-coupler based gain-flattening device for EDFA. Using such a device, flattening of the ASE spectrum of an EDFA is also demonstrated.     

光波导氨敏传感器的研究

提出了一种新型的光波导氨敏传感器,将光波导中消逝波理论与纳米多孔薄膜技术相结合,在玻璃薄膜光波导上制备一层纳米TiO2多孔薄膜,并将氨敏试剂（BTB）固定在纳米TiO2多孔薄膜中,利用导波光的消逝场实时地探测敏感薄膜对导波光的吸收,实现了对氨气的探测,检测下限达到1ppm。同时对比了致密敏感薄膜和多孔敏感薄膜对氨气的响...     

Coupling Losses and Discrimination of Annular Waveguide Laser Resonators

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Coupling Losses and Discrimination of Annular Waveguide Laser Resonators

An approach of calculating the coupling losses in a coaxial (or annular) waveguide laser resonator is developed by which the computational time is considerably reduced. Computations of the coupling losses for some TE modes of an annular waveguide, as a function of mirror curvature and position, are presented in the limit of large mirror aperture. It is shown that there exist three special configurations to provide low coupling losses. The resonator properties are discussed. The calculating results are useful for design of annular waveguide laser resonators.     

YAP晶体光纤弹光效应的研究

利用受扰光纤理论理论和光纤弹光效应理论对ＹＡＰ晶体光纤弹光效应进行了理论分析和实验研究。结果表明，这种晶纤可以弹光调制、压力和加速度传感等方面得到应力，并为该类传感器的设计提供理论根据。     

The Effect of Noncoplanar Winding of an Optical Fiber in a Fiber Ring Interferometer on the Phase Difference of Counterpropagating Waves

We consider a number of photoelastic and geometric-optical physical phenomena arising in a fiber ring interferometer with noncoplanar winding of the fiber ring. It is shown that none of these phenomena can be used to improve the sensitivity of such an interferometer to rotation.     

基于周期极化铌酸锂波导的软件同步光采样

随着大于40 Gb/s高速光通信系统的出现, 为了保证光信号传输质量, 需要对光信号进行监测。对于带宽超过传统光电探测器和示波器可测量带宽的高比特率数据光信号, 光采样技术是进行时域测量的重要手段。采用固定频差的方法可以用百兆速率的采样脉冲对高速光信号进行采样, 降低了对采样后电数据处理系统带宽的要求。在对基于周期极化铌酸锂(PPLN)波导中和频效应的采样过程进行建模仿真的基础上, 实现了对Optsim获得的光传输线内10 Gb/s的非归零码(NRZ)和归零码(RZ)信号的采样。采用软件同步算法对采样数据进行处理, 获得信号的眼图, 这一方法可使采样系统对硬件的要求降到最低。与理想与门获得的采样结果进行比较, 对PPLN波导的光采样特性和采样质量进行了分析。     

基于环形衍射理论的反射式光学系统研究

基于环形衍射理论,对像面光强与光学传递函数进行了计算仿真.编制了可以嵌入到光学设计软件ZEMAX的环形孔径模拟程序,对中心遮拦的像质影响进行了模拟分析.通过理论计算仿真与软件模拟结果对比发现二者结果吻合,验证了嵌入程序的正确性与可行性,为反射式光学系统像质评价提供了更为客观与全面的评价依据.通过模拟结果得出存在中心遮拦光学系统点扩散函数次峰增强,中频区域光学传递函数下降.分别对不同遮拦比像质进行模拟,结果显示对于遮拦比小于30%的系统,遮拦对像质影响基本可以忽略,但当遮拦比增大到40%时,光学传递函数中频开始下降较为明显,为遮拦比的合理选择提供了依据.     

激光输入光纤环形腔内相位调制输出功率谱分析

从理论上详细分析了光纤环形腔有内相位调制时的输出光电流功率谱密度函数，该理论对任意相干长度的输入激光光源都是有效的。理论结果和实验数据表明，过快的相位调制能够平坦光电流功率谱上由于环形腔谐振特性而形成的周期性小峰，而弱相位调制对环形腔输出功率谱则影响不大。     

金属覆层保偏光纤偏振器的五层波导模型及理论分析

对金属履层保偏光纤偏振器建立了五层波导变参量物理模型,设计了自适应套孔爬山法的数值计算方法求解含多层波导本征值的复超越方程,计算结果揭示了金属覆层偏光纤偏振器的物理机制,并对器件进行了优化设计,给出了实验结果。     

光波导振荡场传感器

针对消逝场传感器的不足,提出了一种传感介质处于波导芯层,且以超高阶导模为探针的光波导振荡场传感器.由于其波导芯层处于功率密度极高的振荡场区域,而超高阶导模又具有对芯层参数极为灵敏的性质,因此这种新型传感器的灵敏度大大增强.实现了超越消逝场传感器灵敏度极限值几个量级的位移传感器.     

Numerical and Asymptotic Solution of the Problem of Oscillations of an Inhomogeneous Waveguide with an Annular Crack of Finite Width

Acoustical Physics - The problem of waves in an inhomogeneous cylindrical waveguide with an annular crack is considered. A system of integral equations with hypersingular kernels is obtained for...     

同轴圆筒波导激光器谐振腔的耦合损失及模式特征

计算了同轴圆筒波导谐振腔的耦合损失,结果表明存在三种低耦合损失谐振腔结构,最后分析了谐振腔的模式特性及其设计方法。     

Array Waveguide Grating Based Fiber Lasers

Two array waveguide grating (AWGs) based fiber ring lasers are experimentally demonstrated. Either of them achieves wavelength discrete tuning of 32 nm, or yields simultaneously lasing up to four channels with -7 dBm output power for each channel.